“If you develop industry-, company-, or country-specific enhancements to SAP solutions, the SAP Add-On Assembly Kit can help you plan and deliver those enhancements as software add-ons. The SAP Add-On Assembly Kit guarantees quality software development by using a standardized process flow from planning to delivering the add-on. The delivery tools work smoothly with SAP’s maintenance strategy, helping you integrate new developments into your existing environment and providing maintenance throughout the enhancement’s life cycle. The SAP Add-On Assembly Kit and its comprehensive documentation help ensure high-quality product development from the planning phase. The add-on tools also help you efficiently install, update, and maintain the enhancement.”
In other words if you want to stop deliver your ABAP software via transports, you can request and ask for the AAK. You will get it via an separate contract.
Your ABAP software can even be deinstalled conveniently via the SAP tool SAINT/SPAM.